20w 20

[JakeR22]

I aquired some Penzoil "20w 20" over the weekend. I've never seen this stuff before. It was at a household hazardous waste collection, so I have no idea how old it is.

Is it basically a straight 20 weight oil? What application would this of been for? Probably not good for a car that needs 5w20?

 

[RinconVTR]

No.

 

[sxg6]

I would have no problem using a straight 20wt in the summer time, but chances are its really old stuff. Does it have a GF # or service classifications like sm, sl, etc.

 

[JakeR22]

quote:

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Originally posted by sxg6:
I would have no problem using a straight 20wt in the summer time, but chances are its really old stuff. Does it have a GF # or service classifications like sm, sl, etc.

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I'll have to check on that. Thanks

 

[Bob Woods]

Sounds like oil from the fifties or sixties.

 

[dkcase]

Does it say 20w-20 or 20-20w ??

For some reason, I remember that the weight used to be expressed as 20-20W. I wondered as a kid why it was backwards from the others, like 10W30.

But maybe I remember it just totally wrong .....

 

[Blue99]

Some straight 20 weights are still labeled as 20W-20. Pennzoil continues to carry an SJ rated 20W-20 as part of it's monograde line.

Pennzoil Monogrades

Why the "W" rating? I'm assuming that since 20 weight oil was commonly used as a winter crankcase fill, the 20W label is providing a reference for colder temp operation.

 

[Max_Wander]

Why dont they just call it SAE 20 ? Whats with the need to express that it flows like a 20 at both cold and hot temps. Duh..

 

[XS650]

quote:

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Originally posted by Max_Wander:
Why dont they just call it SAE 20 ? Whats with the need to express that it flows like a 20 at both cold and hot temps. Duh..

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Because some 20 weight oils don't meet 20W.

 

[Max_Wander]

how is that even possible? Whats the diff between 20 and 20w

 

[G-MAN]

The SAE J300 specs actually list cold and hot specs for SAE 20 oil. For an oil to be labeled 20w20, it has to have been tested against BOTH. An oil labeled just SAE 20 need only be tested against the hot specs.

 

[Max_Wander]

Ah, Thank you G-Man !

 

[JohnBrowning]

In Germany as a kid it was known to cause "Black Death" in Opel's running hard on the Autobahn.

 

[Ron AKA]

This graph is a bit busy, but if you look carefully you can see how 20w20 compares to other oils. I think I used Pennzoil specs. Essentially it near a 20 at running temps, close to a Xw30 at 40C (warm), and likely gets worse than Xw30 at cool temps. However, it probably remains better than a 0w40 at fairly cool temps.

No harm in using it in warm climates. Should be relatively free from viscosity breakdown.

 

[Blue99]

Off-topic, but I can remember a period during the seventies (?) when labels listed all the W viscosity grades that the oil matched.

So a 10W-30 was labeled 10-20W-30.

I think the practice was dropped due to the resulting confusion.

 

[JakeR22]

quote:

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Originally posted by Bob Woods:
Sounds like oil from the fifties or sixties.

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I don't think it's that old. It's in a mondern looking plastic container.

 

[WishIhadatruck]

That oil is all my dad ever used in his vehicles starting in the 70's unil sometime in the late 80's. Probably on some mechanic's advice. I haven't see it in years but if it is on their website then obviously they still make it and perhaps it isn't too old?

 

[ebaker]

It used to be a popular "break in oil".

 

[G-MAN]

quote:

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Originally posted by ebaker:
It used to be a popular "break in oil".

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It used to be a popular oil, period. It was the factory fill and a recommended service fill viscosity for the Big Three throughout the 50s and 60s.

 

[LARKBILL]

When I worked at this dealership the first time back in the 80's all they ever used in their bulk tank was 20w20. Keep in mind this was the era of the 10w40 problems and the service manager and one of the owners were very old school.

It was hard to argue with their results though, even then a lot of folks drove the 35+ miles in to St. Louis to work and I saw an awful lot of great running 150K+ mile cars around.